In today's world, blockchains are used for wide variety of applications. A blockchain is a Cryptographic Distributed Ledger (CDL). A distributed ledger is ledger that is replicated in whole or in part to multiple computers. The CDL can have at least some of these properties: irreversibility (once a transaction is recorded, it cannot be reversed), accessibility (any party can access the CDL in whole or in part), chronological and time-stamped (all parties know when a transaction was added to the ledger), consensus based (a transaction is added only if it is approved, typically unanimously, by parties on the network), verifiability (all transactions can be cryptographically verified).
A distributed ledger is a continuously growing list of records that typically apply cryptographic techniques such as storing cryptographic hashes relating to other blocks. A blockchain is one common instance of a distributed ledger and may be used as a public ledger to store information. Although, primarily used for financial transactions, a blockchain can store various information related to goods and services (i.e., products, packages, status, etc.). A decentralized scheme provides authority and trust to a decentralized network and enables its nodes to continuously and sequentially record their transactions on a public “block”, creating a unique “chain” referred to as a blockchain. Cryptography, via hash codes, is used to secure an authentication of a transaction source and removes a central intermediary. A blockchain is a distributed database that maintains a continuously-growing list of records in the blockchain blocks, which are secured from tampering and revision due to their immutable properties. Each block contains a timestamp and a link to a previous block. A blockchain can be used to hold, track, transfer and verify information. Since a blockchain is a distributed system, before adding a transaction to the blockchain ledger, all peers need to reach a consensus status.
Conventionally, timestamps of documents in the blockchain ledgers are established based on the timestamp indicating when the document was registered into the blockchain ledger. However, because a distributed ledger functions by having multiple parties attempt to ledger the data entry, the time lag between the time the data entry is requested to be logged and the time the data entry is indeed logged is mathematically undefined. In practice, a document may receive a timestamp hours after the original request to ledger the entry associated with this document is made. Furthermore, conventional implementations do not validate the document author and the integrity of the timestamp generated by a Time Server.
Accordingly, what is needed is an efficient and robust method for establishing precise time consensuses in blockchains.